Northeast Greenland is a sink for atmospheric methane

Net regional methane sink

in High Arctic soils of northeast Greenland. We conclude that the ice-free area of northeast Greenland acts as a net sink of atmospheric methane, and suggest that this sink will probably be enhanced in a future warmer climate.

Arctic tundra soils serve as potentially important but poorly understood sinks of methane which act as an important greenhouse gas in the atmosphere. Improved knowledge on methane consumption in the dominating dry arctic soils is needed in order to understand the total methane exchange budget in the High Arctic which is conceptually biased as being a net methane emitter. In this CENPERM publication, we present measurements of rates of methane consumption in different soil and vegetation types within the Zackenberg Valley in northeast Greenland. The results show a clear picture of methane uptake in all non-water-saturated landforms studied with higher uptake rates in drier soils.Methane oxidation rates was sensitive to increasing temperatures, indicating that future arctic warming could increase the overall importance of the High Arctic methane sink.

Extrapolation of our measurements and known wetlands fluxes using satellite based land cover classification, we conclude that the ice-free area of northeast Greenland acts as a net sink of atmospheric methane, and is likely to be increased in a future warmer climate.